On space vehicles, deployable appendages, such as antennas, sensor booms, solar arrays, etc., which are relatively fragile and bulky, must be rigidly fixed in a folded or retracted state to the spacecraft structure so as to be protected against stresses during launch. After launch and when the satellite or space vehicle is in orbit, these appendages must be released and deployed so that they can perform their functions.
Bolts that can be cut on command, generally by firing a pyrotechnic device, are the means most commonly used in such mechanisms for fixing moving parts to fixed parts. Such bolts are of the prestressed type or of the type having a weakened zone, and when they are cut they give rise to particles or metal fragments having high kinetic energy that can lead to various kinds of risks, such as short circuits, mechanism jamming, damage to waveguides, etc . . . .
In an attempt to mitigate these drawbacks, proposals have already been made to replace such bolts by stranded metal cables optionally provided with outer coatings of plastic. Cutting such cables produces fragments that are smaller in size than those of metal bolts, but there are always large quantities of them. In addition, the mechanical constraints related to using cables that are relatively flexible limit the range of possible applications.
Proposals have also been made to use bolts of synthetic material, capable of being cut by melting using a hot conductor wire heated by the Joule effect. Cutting in this way does not produce any splinters or fragments of material, but it does cause organic compounds to be vaporized and this can cause unacceptable pollution in a satellite or a space vehicle, in particular since the compounds are likely to be deposited on optical components.
The invention seeks to avoid all of the prior art drawbacks associated with using bolts that can be cut on command. An object of the invention is to provide a device giving protection against the debris produced by a metal bolt that is cut on command, in particular by pyrotechnic means, the device serving to trap in a small space all of the metal debris produced by a bolt on being cut.
Another object of the invention is to provide a device of this type capable of being used with a very high degree of reliability in satellites or space vehicles.